Deep Energy Retrofits: Planning for the Long Haul.

Energy efficiency expert and godmother of Affordable Comfort Inc., Linda Wigington, is a strong proponent of deep energy reductions, a philosophy she has put into action both in her own house and in the foundation of the Thousand Home Challenge. I recently heard Linda speak during the Energy Retrofits for Houses conference in Toronto. I found her position on reducing home energy use to be both relentlessly aggressive and optimistic. 

"The gap between business as usual and the emerging climate goals represents a chasm..." 

A central component of Wigington's argument is that Deep Energy Reductions - reducing the energy usage in a house by 70-90% - are not only possible but essential. Smaller reductions won't do enough to keep home energy costs manageable in an era of substantially increased prices, which are destined to be at least volatile, and likely staggering over the next few decades. Nor are smaller deductions sufficient if your goal is to have an impact on climate change. This is true not only because buildings are responsible for a staggering 40% of carbon emissions, but also because buildings last a long time. Given the half-life of carbon emissions, our emissions (and those of our existing houses, which will presumably outlast us) will be around for 3 or 4 generations.  A little tweak here and there isn’t going to do much to reduce the heft of that legacy. To believe otherwise is to suffer from what Wigington calls "a disconnect.”

Have A Road Map ... and a Destination.
Many of us set out to save between 5-20% in heating and cooling costs by air sealing and insulating our homes. Some of us no doubt believe that over time our efforts will result in the more significant (deep energy) reductions about which Wigington speaks. We view the process of sealing up our homes bit by bit as a natural progression toward ever-increasing efficiency.

This slow and steady process, fostered in part by the stimulus package, sounds reasonable. And it may be. But Wigington points out that these steps are best taken within the context of the potential for deeper energy reductions down the road.  "Weatherizing" and "deep energy reductions" may be two different destinations on a map, particularly if our focus is primarily cost-effectiveness.

In order to limit the possibility that the steps we take now to make our homes more energy efficient will need to be redone or undone in order to attain deep energy milestones, Wigington recommends that homeowners begin this process with a long-haul destination on their road map. It might be 10 years before that destination comes into view, but it nevertheless will guide every step you take along the way.

With regard to air sealing, the long-term destination will require doing the work very well - driven not by what's easiest - and keeping in mind combustion safety and indoor air quality. In the instance of insulation, the long-haul destination will dictate making informed choices about what you're insulating and what you want to include in the thermal boundary. Finally, the long-haul deep energy reduction destination will govern decisions about mechanicals, including ventilation, space and water heating.

The goal: a step by step approach in which you do each step as well as you can, with as little chance as possible of having to redo. Wigington likens the process to a chess game. Take steps that open doors, rather than steps that limit your options.  Consider increasing the r-value of attic insulation, and while you're at it, address potential air quality issues you might face down the road. That will open up the potential for more air-sealing options and high efficiency mechanicals. And it will substantially limit the risk of locking yourself in a corner.

Long-Term Goals
This approach is familiar to any homeowner whose budget prevents taking on the entire house all at once. In our case, we renovated the rotting upstairs bathroom and took out the second floor apartment as soon as we moved in. The kitchen renovation is going to have to wait until we win the lottery. That said, we know that we will renovate the kitchen some day. That knowledge dictates that we not invest in anything that will make that future renovation more difficult, cumbersome, or expensive. We will not replace the floor now, because when we (ultimately) replace the kitchen we know it will get ripped up. We will not change the circuitry in the small room behind the kitchen or buy expensive furniture to meet its zany petit dimensions, because it may all be rendered moot when we replace the kitchen. But we did paint the kitchen walls a lively color, and we did buy used furniture to make that back room serviceable.

As I see it, Wigington's approach to 90% is my beautiful some day kitchen. It is the goal -however distant -  that guides all decisions. Sure it makes sense to insulate and air seal, just like it does to paint and (shoddily) furnish our back room. But does it make sense to invest in a new heating system in your unfinished basement? Maybe. Maybe not.

Know Your Spaces.

An unfinished basement is an ambiguous indoor/outdoor space, and a truly energy efficient house will not tolerate such spaces. So with your long-term goal in mind, decide whether you will someday convert that basement to indoor space (in which case it needs to be dry and insulated).  If you don't plan to integrate your basement, then don't invest in a heating system that will require you to dry out and insulate a space that could effectively be isolated from the house, saving reams of heating waste and cost and increasing the overall health of your house.  That said, in most cases creating a dry insulated basement is the preferred solution. And it is better to do that work (at least adjacent to and under the furnace) while the furnace is being replaced.

The long haul goal will also help you think through the purchase of a high efficiency furnace. It's a good step - but is it the best step? Might a combination system that provides both efficient warm water and efficient heat be a better long-term choice? Find out.

Wigington does not so much condemn the small steps as ask that they be put in perspective, and seen as part of a larger whole.  She has witnessed the disappointment of homeowners  who have spent days caulking the sealing the interior of their houses only to find that the blower door tests after all that work showed little improvement. Likely, that's because the homeowner neglected to recognize that the attic was by far the biggest leakage issue for the house. Nothing short of tackling that major problem was going to bear the kind of fruit the homeowner sought.

As a homeowner seeking to create a healthy, efficient home with a small carbon imprint, consider that a deep energy retrofit is possible. Maybe that means shifting priorities on your road map, but by keeping that destination in your sights, you may be spared the frustration of a wrong turn. Wigington describes this appraoch as a paradigm shift. She may be right. And I'm not sure it's going to be an optional shift for long.